Gripper system of a sheet-fed printing press

Abstract

Gripper system of a sheet-fed printing press, comprising a gripper system body on which a gripper shaft is mounted, wherein grippers are attached to the gripper shaft which can be displaced relative to gripper supports provided by the gripper system body by rotating the gripper shaft, characterized by at least one sheet deformation device (16; 23; 30) that can be controlled independently of the grippers (13), wherein, with the aid of the or each sheet deformation device, a printed sheet grasped between the grippers (13) and the gripper supports (14) at a sheet edge can be deformed at each position of the same, thereby increasing the bending stiffness of the printed sheet.

Description

[0001] The invention relates to a gripper system, in particular a delivery gripper, of a sheet-fed printing press according to the preamble of claim 1.

[0002] The basic structure of a gripper system for a sheet-fed printing press is known from EP 1 004 438 B1. The gripper system disclosed therein comprises a gripper system body on which a gripper shaft is mounted. Grippers are attached to the gripper shaft and can be moved relative to the gripper system body and relative to gripper supports provided by the gripper system body by rotating the gripper shaft. When the grippers attached to the gripper shaft come into contact with the gripper supports, a printed sheet can be gripped at its edge. When the grippers are lifted or pivoted away from the gripper supports, a gripped printed sheet is released by the gripper system.

[0003] DE 10 2007 047 447 A1 relates to a method for conveying a sheet through a printing machine, wherein the position of a sheet edge is to be improved during transfer between two gripper systems. The invention consists in a method for conveying a sheet through a printing machine, in which the sheet is moved along a conveyor track and transferred at a sheet edge from one gripper system to another gripper system. In gripper systems with several grippers arranged in a row, a movement of the sheet at the sheet edge perpendicular to the conveying direction is restricted prior to transfer. The movement can be restricted by mechanical stops, by deformations at the sheet edge, and by pneumatic or electrical forces.

[0004] A printed sheet gripped by a gripper system in the area of ​​a sheet edge is transported through areas of the sheet-fed printing press, for example through a delivery thereof, with the aid of the gripper system. In order to improve the so-called sheet travel behavior of a printed sheet to be transported during such transport, it is already known from DE 10 2007 033 931 A1 to adjust the grippers of a gripper system using adjusting means in order to impart a defined transverse deviation to the sheet edge of the printed sheet gripped by the gripper system. This can increase the flexural rigidity of the printed sheet and improve the sheet travel behavior. However, adjusting the grippers of a gripper system is structurally complex. There is therefore a need for a gripper system for a sheet-fed printing press in which the sheet travel behavior of gripped printed sheets can be improved using simpler means.

[0005] Based on this, the present invention is based on the problem of creating a novel gripper system for a sheet-fed printing press. This problem is solved by a gripper system according to claim 1. The gripper system according to the invention comprises at least one sheet-deforming device that can be controlled independently of the grippers. With the aid of the or each sheet-deforming device, a printed sheet gripped between the grippers and the gripper supports at a sheet edge can be deformed at a respective position thereof, thereby increasing the flexural rigidity of the printed sheet. A gripped printed sheet can be deformed in the area of ​​its free edges using a sheet-deforming device.

[0006] The gripper system according to the invention has at least one sheet deformation device that can be controlled independently of the grippers. With such a sheet deformation device, it is possible to deform a printed sheet gripped at a sheet edge between the grippers and the gripper supports of the gripper system, thereby increasing the flexural rigidity of the printed sheet, without displacing or adjusting the grippers. This allows sheet travel behavior to be improved using simple means.

[0007] According to a first advantageous development of the invention, the or each sheet deformation device has opposing longitudinal struts, wherein a first longitudinal strut faces a printed sheet to be deformed and a second longitudinal strut faces away from the same, wherein the longitudinal struts are connected directly at a first end and subsequently indirectly by cross struts, wherein an actuator is assigned to a second end of at least one of the longitudinal struts in order to exert a force on the same substantially in the longitudinal direction of the respective longitudinal strut and thus to enable a relative movement between the longitudinal struts and the cross struts with the first longitudinal strut facing the printed sheet to be deformed bearing against the printed sheet to be deformed.

[0008] According to a second advantageous development of the invention, the or each sheet deformation device is designed as a sleeve slidably mounted on the gripper shaft with a projection projecting substantially radially relative to the sleeve, wherein upon rotation of the gripper shaft the gripper but not the or each sheet deformation device is rotatable, and wherein an actuator is assigned to the or each sheet deformation device in order to exert a force or a moment on the same and thus to enable a rotational relative movement between the sleeve of the respective sheet deformation device and the gripper shaft with the projection of the respective sheet deformation device resting on the printed sheet to be deformed.

[0009] According to a third advantageous development of the invention, the or each sheet deformation device has a blade-like deformation element which can be translationally displaced in its axial position relative to the gripper shaft.

[0010] Preferred developments of the invention will become apparent from the dependent claims and the following description. Exemplary embodiments of the invention are explained in more detail, without being limited thereto, with reference to the drawings. Herein: Fig. 1a shows a detail of a gripper system according to the invention of a sheet-fed printing press according to a first embodiment of the invention in plan view; Fig. 1b a detail of the gripper system of the Fig. 1a in perspective view; Fig. 2a shows a detail of a gripper system according to the invention of a sheet-fed printing press according to a second embodiment of the invention in plan view; Fig. 2b a detail of the gripper system of the Fig. 2a in perspective view; Fig. 3a shows a detail of a gripper system according to the invention of a sheet-fed printing press according to a third embodiment of the invention in plan view; and Fig. 3b a detail of the gripper system of the Fig. 3a in perspective view.

[0011] The present invention relates to a gripper system for a sheet-fed printing press. The gripper system according to the invention is preferably designed as a cantilever gripper.

[0012] Fig. 1a and Fig. 1b show a first embodiment of a gripper system 10 according to the invention for a sheet-fed printing press. The gripper system 10 of the Fig. 1 has a gripper system body 11, on which a gripper shaft 12 is rotatably mounted. Grippers 13 are attached to the gripper shaft 12, whereby Fig. 1a shows only one gripper 13 of the gripper system 10 attached to the gripper shaft 12. Several such grippers 13 are attached to the gripper shaft 12, side by side, in the axial direction of the gripper shaft.

[0013] The grippers 13 of the gripper system 10 can be rotated by rotating the gripper shaft 12, specifically relative to gripper supports 14 provided by the gripper system body 11. When a gripper 13 rests against a gripper support 14, a printed sheet can be gripped at a sheet edge in the area of ​​the gripper. However, when such a gripper 13 is lifted from the gripper support 14, the gripper 13 releases the sheet edge of the printed sheet.

[0014] The Fig. The gripper system 10 shown in detail in Figure 1a can be transported through sections, in particular a delivery, of a sheet-fed printing press by means of a circulating conveyor belt system (not shown), whereby a printed sheet gripped by the gripper system 10 is ultimately conveyed through the corresponding area of ​​the sheet-fed printing press.

[0015] Relevant elements of the gripper system 10, which interact with the circulating conveyor system (not shown) of the printing press, are arranged in particular on both sides of the gripper system 10 in a corresponding receptacle 15, wherein Fig. 1a only shows such a recording 15 schematically.

[0016] In order to improve the sheet travel behavior of a printed sheet gripped by the gripper system 10 during its transport by means of the gripper system 10, the gripper system 10 has, according to the invention, at least one sheet deformation device 16 which can be controlled independently of the grippers 13 thereof, wherein Fig. 1a shows only one such sheet forming device 16, and wherein Fig. 1b shows such a sheet deformation device 16 in a single representation.

[0017] By means of the or each sheet deformation device 16, a printed sheet gripped between the grippers 13 and the gripper supports 14 at a sheet edge can be deformed, increasing its flexural rigidity. Each sheet deformation device 16 deforms a gripped printed sheet at a position thereof, namely at the free edges of the printed sheet. This deformation increases the flexural rigidity of a gripped printed sheet normal to the sheet edge.

[0018] The Fig. 1a and Fig. The sheet deformation device 16 shown in Figure 1b has two opposing longitudinal struts 17 and 18. A first longitudinal strut 17 faces a gripped printed sheet to be deformed, whereas a second longitudinal strut 18 faces away from the sheet. The longitudinal struts 17 and 18 are directly connected to one another at a first end 19 thereof, with the longitudinal struts 17 and 18 then being indirectly connected to one another in sections via cross struts 20. An actuator 22 is assigned to a second end 21 of at least one longitudinal strut, opposite the first end 19, in the illustrated embodiment, the longitudinal strut 17.

[0019] Via the actuator 22, a force F extending substantially in the longitudinal direction of the respective longitudinal strut 17 can be exerted on the same in order to enable a relative movement between the longitudinal struts 17 and 18 and the transverse struts 20 with deformation and contact of the longitudinal strut 17 facing the printed sheet to be deformed against the printed sheet to be deformed.

[0020] By applying a force F extending essentially in the longitudinal direction of the strut 17, the longitudinal strut 17 can be deformed and brought into contact with the printed sheet to be deformed.

[0021] The two longitudinal struts 17 and 18 of the arch deformation device 16 are elastically or articulately connected to one another between the first end 19 and the second end 21 via the transverse struts 20.

[0022] The or each sheet forming device 16 of the embodiment of the Fig. 1a and Fig. 1b engages the gripper system body 11 but not the gripper shaft 12, in such a way that the longitudinal struts 17 and 18 extend substantially perpendicular to the axial direction of the gripper shaft 12.

[0023] In Fig. 1a shows only one sheet deformation device 16, which is positioned laterally outside next to an outer gripper 13 and deforms a gripped printed sheet at a free edge of the printed sheet, increasing its flexural rigidity. At the opposite edge of the printed sheet, the same can be deformed by another sheet deformation device 16, also increasing its flexural rigidity, wherein then Fig. 1a, not shown, on the opposite end of the gripper shaft 12, a further sheet deformation device 16 is positioned laterally outside next to the corresponding outer gripper 13 of the gripper system 10.

[0024] In the example of Fig. 1a and Fig. 1b, at least one sheet-forming device 16 is used to deform the printed sheet in the gripped state. This device has two longitudinal struts 17, 18 connected to one another by transverse struts 20. By applying force to one of the longitudinal struts 17, the sheet-forming device 16, namely the longitudinal strut 17 facing the sheet to be deformed, is deformed and thus comes into contact with the printed sheet to be deformed, so that the sheet can be deformed at at least one edge of the sheet, increasing its flexural rigidity. This improves the sheet travel behavior of the printed sheets to be transported.

[0025] The actuator 22 of the sheet deformation device 16 can be designed as an electrical actuator, as a mechanical actuator, as a pneumatic actuator or as a piezo actuator or as a magnetic actuator.

[0026] The longitudinal struts 17 and 18 as well as the transverse struts 18 of the arch deformation device 16 are preferably designed as metallic sheets.

[0027] A gripper system 10' according to a second embodiment of the invention shows a Fig. 2a and Fig. 2b. Also in the variant of Fig. 2a and Fig. 2b, the gripper system 10' has at least one sheet deformation device 23 which can be controlled independently of the grippers 13 of the gripper system 10' and via which a printed sheet gripped between the grippers 13 and gripper supports 14 can be deformed at least in one position, increasing the flexural rigidity of the printed sheet, namely at free edges of the printed sheet.

[0028] In the example of Fig. 2a and Fig. 2b, the respective arch deformation device 23 is formed by a sleeve 24 and a projection 25 projecting substantially in the radial direction relative to the sleeve 24.

[0029] The sleeve 24 of the respective sheet forming device 23 is slidably mounted on the gripper shaft 12 of the gripper system 10', so that when the gripper shaft 12 is rotated, the gripper 13 is rotated but not the sleeve 24 and thus the sheet processing device 23.

[0030] The arch forming device 23 of the Fig. 2a and Fig. 2b is assigned an actuator (not shown) in order to exert a force or a moment on the respective sheet deformation device 23, and thus to enable a rotational relative movement between the sleeve 24 of the respective sheet deformation device 23 and the gripper shaft 12 with the projection 25 of the respective sheet deformation device 23 resting on the printed sheet to be deformed.

[0031] In the example shown, the Fig. 2a and Fig. 2b, the projection 25 of the respective arc-deforming device 23, which projects substantially radially relative to the sleeve 24, has three sections 26, 27 and 28 which are angled relative to one another. Fig. 2b, sections 26 and 28 are parallel to each other and are connected by section 27. To deform a gripped printed sheet, section 28 of projection 25 comes into contact with the printed sheet. Other contours of projection 25 are also possible.

[0032] How Fig. 2b shows, the projection 25 can have a bevel 29 or even a phase in the region of the section 26 in order to enable a linear or even planar contact of the projection 25 with a printed sheet to be deformed.

[0033] In contrast to the embodiment of the Fig. 1a, Fig. 1b is in the embodiment of the Fig. 2a, Fig. 2b the or each sheet forming device 23 is not mounted on the gripper system body 11, but rather on the gripper shaft 12.

[0034] In both embodiments, however, the respective sheet forming device 16 or 23 is immovable in its axial position relative to the gripper shaft 12. This is the case in the embodiment of the Fig. 2a and Fig. 2b is achieved in that the corresponding sheet deformation device 23 is secured in its axial position on the gripper shaft 12 by retaining rings 30 which engage in grooves (not shown) on the gripper shaft 12 and secure the corresponding sheet deformation device 23 in its axial position on the gripper shaft 12.

[0035] Just as in the example of the Fig. 1a, Fig. 1b can also be used in the embodiment of Fig. 2a, Fig. 2b, the gripper system 10' may have several sheet deformation devices 23. However, only those sheet deformation devices 23 that interact with a free edge of the gripped printed sheet to be deformed are active. Sheet deformation devices positioned between two grippers gripping a printed sheet in the area of ​​a sheet edge are inactive to prevent the printed sheet from tearing.

[0036] The or each actuator via which in the embodiment the Fig. 2a and Fig. 2b, the arc-forming devices 23 can be rotated relative to the gripper shaft 12, can be implemented electrically, mechanically, pneumatically, or piezo-actuated. Furthermore, the actuator can be based on a magnetic operating principle.

[0037] The examples of the Fig. 1a, Fig. 1b and Fig. 2a, Fig. 2b is that the arc deformation devices 16 and 23 are immovable in their axial position relative to the gripper shaft 12. In contrast, Fig. 3a and Fig. 3b shows an embodiment of a gripper system 10" according to the invention, which has at least one sheet deformation device 30 which is translationally displaceable in its axial position relative to the gripper shaft 12 of the gripper system 10" in order to deform, depending on the grippers 13, a printed sheet gripped between the grippers 13 and gripper supports 14 in the region of a sheet edge, thereby increasing the flexural rigidity of the same.

[0038] For example, the Fig. 3a and Fig. 3b visible arc deformation device 30 via a shovel-like deformation element 31, which is translationally displaceable in its axial position relative to the gripper shaft 12, wherein the arc deformation device engages the gripper system body 11 in a translationally displaceable manner, but is not connected to the gripper shaft 12.

[0039] The blade-like deformation element 31 of the Fig. 3a and Fig. The sheet-forming device 30 visible in Figure 3b has a curved deformation surface 32. When the sheet-forming device 30, and thus the deformation element 31, is displaced axially outward, the deformation surface 32 of the same does not touch a printed sheet. However, when the deformation element 31 of the sheet-forming device 30 is displaced axially inward toward a gripped printed sheet, the deformation surface 32 of the blade-like deformation element 31 touches a free edge of the printed sheet, deforming the same and increasing the flexural rigidity of the printed sheet.

[0040] To displace the arch deformation device 30 of the embodiment of the Fig. 3a and Fig. 3b again serves an actuator not shown, which can be designed as an electrical actuator, mechanical actuator, pneumatic actuator, piezo actuator or magnetic actuator.

[0041] In the illustrated embodiments, the sheet deformation devices 16, 23, and 30 each come into contact adjacent to a free edge of a gripped printed sheet on one side of the sheet, e.g., on the top side thereof. A stop can be assigned to the opposite side of the printed sheet, e.g., on the underside thereof, which limits the deformation of the printed sheet via the respective sheet deformation device 16, 23, and 30, respectively. List of reference symbols 10, 10', 10" gripper system 11 Gripper system body 12 gripper shaft 13 grippers 14 Gripper support 15 recording 16 Arch forming device 17 Longitudinal strut 18 Longitudinal strut 19 End 20 cross brace 21 End 22 Actuator 23 Arch forming device 24 sleeve 15 lead Section 26 Section 27 Section 28 29 Bevel 30 Arch forming device 31 Deformation element 32 Deformation surface

Claims

[1] Gripper system of a sheet-fed printing machine, with a gripper system body on which a gripper shaft is mounted, wherein grippers are attached to the gripper shaft, which grippers can be displaced by rotating the gripper shaft relative to gripper supports provided by the gripper system body, characterized by at least one sheet deformation device (16; 23; 30) which can be controlled independently of the grippers (13), wherein with the aid of the or each sheet deformation device a printed sheet gripped between the grippers (13) and the gripper supports (14) at a sheet edge can be deformed at a respective position thereof, thereby increasing the flexural rigidity of the printed sheet. [2] Gripper system according to claim 1, characterized byin that the or each sheet deformation device (16) has opposing longitudinal struts (17, 18), wherein a first longitudinal strut (17) faces a printed sheet to be deformed and a second longitudinal strut (18) faces away from the same, wherein the longitudinal struts (17, 18) are connected directly at a first end (19) and subsequently indirectly by cross struts (20), wherein an actuator (22) is assigned to a second end (21) of at least one of the longitudinal struts (17) in order to exert a force on the same in the longitudinal direction of the respective longitudinal strut and thus to enable a relative movement between the longitudinal struts (17, 18) and the cross struts (20) with the first longitudinal strut (17) facing the printed sheet to be deformed bearing against the printed sheet to be deformed. [3] Gripper system according to claim 2, characterized bythat both longitudinal struts (17, 18) of the respective arch deformation device (16) are elastically or articulately connected to one another between the first end (19) and the second end (21) via the transverse struts (20). [4] Gripper system according to claim 2 or 3, characterized by that both longitudinal struts (17, 18) of the respective sheet deformation device (16) run perpendicular to the gripper shaft (12) and engage the gripper system body (11) but not the gripper shaft (12). [5] Gripper system according to claim 1, characterized bythat the or each sheet deformation device (23) is designed as a sleeve (24) slidably mounted on the gripper shaft (12) and has a projection (25) projecting radially relative to the sleeve (24), wherein upon rotation of the gripper shaft (12) the grippers (13) but not the or each sheet deformation device (23) are or are rotatable, and wherein an actuator is assigned to the or each sheet deformation device in order to exert a force or a moment on the same and thus to enable a rotational relative movement between the sleeve (24) of the respective sheet deformation device and the gripper shaft (12) with the projection (15) of the respective sheet deformation device (23) bearing against the printed sheet to be deformed. [6] Gripper system according to claim 5, characterized bythat the projection (25) of the respective sheet deformation device (23) projecting in the radial direction relative to the sleeve (24) has a bevel (29) or phase in order to enable a linear or flat contact of the projection (25) with the printed sheet to be deformed. [7] Gripper system according to one of claims 2 to 6, characterized by that the or each sheet deformation device (16; 23) is non-displaceable in its axial position relative to the gripper shaft (12). [8] Gripper system according to claim 1, characterized by that the or each sheet deformation device (30) has a blade-like deformation element (31) which can be translationally displaced in its axial position relative to the gripper shaft (12). [9] Gripper system according to claim 8, characterized by that the or each sheet deformation device (30) acts on the gripper system body (11) but not on the gripper shaft (12). [10] Gripper system according to claim 8 or 9, characterized by that the blade-like deformation element (31) of the respective sheet deformation device (30) has a curved deformation surface (32), wherein when the deformation element (31) is displaced axially outwards, the deformation surface (32) thereof does not touch an edge of a printed sheet, and wherein when the deformation element (31) is displaced axially inwards, the deformation surface (32) thereof touches an edge of the printed sheet, deforming the same.

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